A Theory in Sleep Deprivation
by scarlettwriter11
Summary: After John comes home from a long couple of days at the surgery, he finds an extremely sleep-deprived Sherlock, attempting to build a time machine. Prompt requested by someone on dA
1. A Fiasco in Time

It had been a trying day at the surgery, and as John walked up the steps to his, no, _their_, flat, he had a feeling that whatever was in that flat was not going to help him in the slightest.

It had been five months since Sherlock's return. After he had explained everything to a very confused, poignant, and belligerent John what the nature of his actions had been, and what he had accomplished in the three years past, John was more or less okay with the new situation. Well, things didn't go as smoothly as Sherlock had hoped they would because John at the time was thoroughly convinced that he was either going off the mend, or the victim of some cruel joke. John had gone so far as to kick Sherlock out of the flat, only to let him back in the next day, broken and on the verge of tears whilst explaining the cause of his unstable behavior. Sherlock's return had most certainly been shocking, almost horrific for John. But, it was as if he had been awoken from some kind of stupor. To see that bloody idiotic, brilliant man standing his doorway, no, _their_ doorway, was like no other feeling John Watson had ever experienced before. It was relief and that grim satisfaction of being right all rolled into one card. Sure, the scars were still visible and had clear signs of never fading completely, but the fact that they were no longer raw wounds was saying something.

At first, the two men struggled to get things back to "normal", if you could call what they had before as normal. But, after they had solved, or rather, after Sherlock had solved their first case since Sherlock's "death", things fell into place more or less.

Sherlock was different though. He was more, compassionate towards John, in a way, kinder than he ever was before the Fall. He listened to John's every word like they were the most important utterances ever spewed from the mouth of a man. He offered to do things for John that he would have never have done in the past, such as, make breakfast, or even go so far as to buy milk. John suspected that this changed behavior was due to the fact that Sherlock was trying to make up for what he had done, how he had made John feel, how he had hurt John. And although John was flattered by this sudden attention from the world's only consulting detective, he felt there was something odd about it. Like there was something missing.

In a way, he missed the arrogant, snippy attitude of the detective. Yes, it could be unpleasant at times, and yes, it would occasionally hurt John's pride, but, that was what made John fond of the man in the first place. He always identified Sherlock as the man who didn't give a rat's arse what anyone thought of him, and that he was going to continue going about things in his own, peculiar manner, no matter what. John admired that about him. He admired his independence and uniqueness. He just really wanted the old Sherlock back, _his_ Sherlock, and not this falsely-kind, lying-to-make-you-feel-better Sherlock, (and John knew Sherlock was lying to him when he called him 'brilliant' or 'spot on'). Not that this Sherlock wasn't _nice_, it just wasn't, _him_.

So as John put a hand on the doorknob to _their _flat, he had no idea what he would find, and he was not sure whether he liked that feeling of uncertainty or not. Sherlock had always been unpredictable, that's what made him exceptional, but lately, this unpredictable Sherlock was not one John wanted to make conversation with. Opening the door, however, did not help matters in the slightest.

Sherlock was on John's laptop, strands of his curly mop stuck out in every odd direction as if he had run his hands through them a dozen times. His eyes were bloodshot as he read furiously, his dressing gown hanging off one shoulder unevenly. He had several fat books laid open around him on the floor, and occasionally would absentmindedly rifle through one, then abandon the effort, quickly typing out something on the laptop. A fine shadow of stubble covered his jaw line. He noticed at least three nicotine patches peaking out from underneath the sleeve of his dressing gown. John had only been gone two days on call, in which he thought that Sherlock would continue being his boring, new, careful self while he was away. But apparently, John had thought wrong. This Sherlock vaguely reminded John of the old Sherlock he knew so well. He smiled faintly, and ventured forward.

"Sherlock? What're you doing?" John said, bending down to pick up one of the books.

"Don't touch!" Sherlock snapped, pointing a strict finger at John, his eyes still glued to the screen. John froze and stared at Sherlock. "Set it back down," Sherlock mumbled, typing, then he paused. "Please." he murmured, then continued to type. John raised an eyebrow, but carefully set the book back down.

"Sherlock, are you going to answer me?"

"Hmm?"

"Sherlock, look at me." John said sternly, and Sherlock's glazed eyes slowly pried themselves from the screen to focus on John. John opened his mouth to say something, but then Sherlock's eyes widened as if he were just seeing John for the first time. Sherlock shoved the laptop aside and sprang up, looking oddly like a deranged kangaroo. He grabbed John's shoulders and looked him straight in the eyes, his own eyes glistening with manic glee.

"John! I have it! I have the solution!" Sherlock said delightedly, grinning in a rather frightening manner. John scrunched his eyebrows together, puckering his lips out in confusion.

"Solution?" John said slowly. Sherlock rolled his eyes and waved his hand impatiently.

"Yes! The solution to our problem!"

"What problem?" Sherlock groaned and stepped back, grabbing the laptop and cradling it with one arm while using the other to navigate on the mouse pad.

"The problem John!" Sherlock said, his eyes wide as he stared at the screen. "I've been reading up on time travel theory this past week, all very fascinating, I don't know why I haven't read up on it before, but from what I've read, it is possible! Do you know what this means John?"

"That, you've been watching too much Doctor Who?" Sherlock gave John a blank look, then continued talking.

"It means, that with this knowledge, I can fix our problem!"

"What're you going on about, _our problem_? What problem Sherlock?" Sherlock hastily put the computer down on the chair and grabbed John by his shoulders once more, staring into his eyes with intense desperation.

"Moriarty." Sherlock hissed. John raised an eyebrow, a little frightened now by Sherlock's behavior.

"Moriarty is dead Sherlock."

"Yes, but look at what he's done to us! He tore us apart, planted the seed of doubt in the minds of the people I've helped. If we went back in time, we could potentially rid the world of Moriarty before he ever caused havoc on our lives! Don't you see, it's brilliant!" Sherlock said with a wide grin. John firmly put his hands on Sherlock's forearms and pried him off him. He led Sherlock to the couch where he forced him to sit. Sherlock still had that look of excited insanity in his eyes. John sat before him on the coffee table and looked Sherlock squarely in the eye.

"Sherlock, when was the last time you slept?" John asked in his most professional voice. Sherlock rolled his eyes and waved his hand at John as if he were an annoyance.

"Irrelevant. What is relevant however, is my theory. I-"

"Sherlock, answer me." Sherlock's attention zeroed back in to John again as he picked up on his change of tone.

"Five days ago." John's eyes widened for a moment before he resumed his cool, collected demeanor.

"Okay, Sherlock, you do realize, that lack of sleep can have serious effect on brain function, right?" Sherlock's brows furrowed for a moment, then his face cleared as if an epiphany suddenly dawned on him.

"Of course!" Sherlock said, jumping up. "You are absolutely correct! I knew there was something wrong!" Sherlock said, striding back over to his chair. John sighed in relief.

"Good, now, get some re-"

"Don't you see John? I've calculated all wrong. I knew there was something missing from my equation, but now that you've brought to light some rather significant evidence, which means I can proceed with my theory!" Sherlock said giddily. John stood and gaped at him.

"What, Sherlock, no! That's not at all what I meant!"

"But it makes perfect sense John!"

"No Sherlock, it doesn't."

"Well of course you wouldn't understand."

"And what is that supposed to mean?"

"It means you're an idiot." John's lip twitched with the sudden urge to smile, but he suppressed it. As much as he enjoyed having the old Sherlock back, this Sherlock was far more mental than was healthy for either of them.

"Sherlock, this, time travel stuff. It's a load of bull."

"Please John, don't mock such an-"

"Sherlock!" John said angrily. Sherlock stopped talking and stared at John warily. "You haven't slept in five days, yeah? Sleep deprivation, it tampers with your reasoning you dolt! So no matter how much you convince yourself that time travel will work and that you can change the course of time, you can't Sherlock! You're not thinking properly, you've invented this crazy scheme, you've been driving yourself up the wall thinking about stupid, crazy things that you can't help. Moriarty is dead. Yes, he screwed us over pretty bad, yes, he made you fake your own death, but that doesn't matter anymore Sherlock," John softened some and put his hand on Sherlock's shoulder. "Because, you're back, and you're brilliant as ever. So, stop this madness, and get some bloody sleep! Doctor's orders." Sherlock frowned in confusion at John, then he seemed to deflate a little. His eyes drooped and he sighed.

"John, I'm sorry."

"It's alright, just go to sleep."

"But, my theory…"

"Sherlock." Sherlock exhaled childishly and rolled his eyes.

"Very well, I will get some sleep, for you." John shook his head good naturedly at Sherlock and steered him in the direction of his bedroom. John shut the door behind Sherlock and wearily went back into the living room, where he surveyed the mess that Sherlock had left behind in his sleepless reverie.

He spent half an hour tidying up, restacking papers, fluffing the pillows, washing tea mugs, and taking back his laptop. When he was done, he was looked over his handiwork, tired, but satisfied. He decided to check back in on Sherlock before he made himself some dinner and went to bed. Opening the door, John slowly poked his head in Sherlock's room, where he saw Sherlock sprawled out haphazardly on his bed, mouth open slightly. He was fast asleep. John smiled, making his way quietly into the bedroom.

He crept over to the bed and pulled Sherlock's covers over him, making Sherlock stir slightly in his sleep. John watched the man for a moment, then perched himself on the edge, just watching Sherlock sleep.

He had missed Sherlock terribly, so much that it had ached, but he also resented him for what he had done. He never thought he would see this face again, and wasn't sure he had wanted to, after all the pain he had put him through. But now, watching Sherlock breath deeply, completely at ease, John knew that he was glad to have Sherlock back. _His_ Sherlock back. And he knew Sherlock was sorry, for Christ's sake, the man tried to build a time machine to fix things. But John had forgiven him the moment he had seen him on his doorstep, _their_ doorstep, without even realizing it himself. Because John loved this man, and he was glad to have him home once more.

John reached out a hand to stroke it over Sherlock's forehead where a few stray curls rested. Sherlock stirred again and his eyes fluttered open, staring about the room in momentary confusion until they rested on John's face.

"I did it for you John." Sherlock whispered hoarsely. John smiled.

"The time machine, yeah, I know." Sherlock shook his head.

"No, everything before. It was all for you. It had always been for you. Always." John stroked Sherlock's forehead again and nodded.

"Yes Sherlock, I know. Thank you." Sherlock nodded sleepily, then closed his eyes once more and drifted back to sleep. John leaned forward and pressed his lips on Sherlock's forehead. Then he pulled back an inch or so, hand resting in Sherlock's black curls.

"Thank you." he whispered, then got up and left the room, leaving Sherlock to get some much-needed sleep.


	2. Epiphany

John needed Sherlock. And Sherlock needed John. That much was clear, especially after those grueling three years, which had been just as painful for Sherlock as it had been for John. He knew he had hurt John, he knew John had missed him more than he let on, but everything seemed to click for Sherlock the morning after his time machine fiasco. Whether John knew that Sherlock had been asleep or not when he kissed him on the forehead, Sherlock had absolutely no idea, which frustrated him greatly. He was usually so keen to John's motives and actions, but that had truly been a surprise for Sherlock. But, what was even more surprising to Sherlock, was his own reaction to the kiss. He remembered feeling John's warm lips, the scrape of his stubble, and feeling content, at ease. Something he rarely experienced. He remembered very vividly, despite his sleep deprived state, that when John's lips left his skin, he craved their touch once more.

Sherlock may be a tad ignorant when it came to human emotions, but he was no fool. He knew what this meant, what John meant to him, or rather, what John had always meant to him, something he had overlooked in the past apparently. But with this new data, this new piece of information, that John might possibly return those feelings, made things slightly easier for Sherlock. Or challenging. It just all depended on how he went about this delicate situation. But Sherlock wasn't simply going to sit back and wait for something to happen. He had to take action, for fear of losing John for good. He couldn't lose John, especially not after all that he had done to keep him.

"John?" Sherlock said as they sat together in their separate chairs, doing their separate things. Sherlock had never been an idle man, but it was times like these where it seemed rather nice to just sit and enjoy another person's company, regardless if they talked or not. Well, not just any person's company. John's company was the one he preferred above all. He had missed this, this gentle quietness that seemed to settle over the two of them comfortably.

"Mm?"

"Would you have stayed in the army if you hadn't been discharged?" John looked up from his laptop slowly, his brows furrowing.

"Why're you asking that? I thought you might have worked that out already." John said quietly.

"John, I don't ask questions that I already know the answers to." John sighed and closed his laptop.

"Sherlock, this isn't something I really want to talk about right now."

"When then?"

"What?"

"When would be a good time to talk about it?" John stared at Sherlock for a moment, apparently incapable of speech.

"Why do you care?"

"Because, it interests me."

"Why?"

"Because John, now answer the question, please." John grumbled and sat back his chair, glaring at Sherlock. He sighed in defeat.

"Yes."

"Why?" John pursed his lips together in frustration.

"I dunno Sherlock, because, it gave me a purpose."

"And if you hadn't met me?" John didn't say anything.

"I don't understand the question."

"If you hadn't met me John, do you think you would have been the same, better off perhaps?" John gaped at Sherlock.

"I, what? What are you on about Sherlock?" Sherlock sighed while rising to stand, and started to pace about the flat.

"If you had never met me, if Mike had never introduced you to me, how do you think you would have carried on living? Do you think you would have been happier? Safer? Does it ever occur to you that I might hold you back? Hinder your progress as a recovering war veteran?"

"Stop," John said, standing up. Sherlock stopped pacing and faced John, who looked very determined. "Just, stop, okay? When I thought you were, dead, I didn't know what to do. Yeah, sure, I moved on, but it wasn't easy. I didn't like it. I missed you every day that you were gone," John's face had hardened as he stared intently at Sherlock, as if his stern voice wasn't enough to get through to Sherlock. Sherlock tried his very best to keep from grinning. "But, when you came back Sherlock, I felt, well, I felt whole again. So don't you bloody think for one second that I would have been happier if I hadn't met you. I would have been lost." John's fists were balled up at his sides, clenching and unclenching again as he stared down Sherlock who gazed back at him in wonder.

And there it was. Just what Sherlock had been looking for. Everything fell into place. And now for the final step that would truly make his theory airtight.

He slowly stepped toward John, making sure to maintain eye contact with the man. John watched him warily, but didn't say anything as Sherlock made his way toward him. Good, that was good. It meant John wasn't going to stop him. He was about a foot away, looking down at John before taking his face between his hands. John looked tired, new wrinkles lining his face. But he certainly looked a lot healthier since Sherlock had made his return, which made Sherlock smile. He closed his eyes, and pressed a gentle kiss on John's forehead, just as John had done to him the night of the time machine. He heard John take a slight intake of the breath, but then gradually leaned in the soft kiss.

They stood like this for a few moments, soaking in each other's warmth. Then Sherlock pulled back and looked John squarely in the eyes. He breathed out a contented sigh and smiled again at John, who smiled weakly back.

"You are fantastic John Watson." John smirked slightly and shrugged.

"Sure okay. Can I ask, what that was for?"

"It's obvious."

"It isn't obvious to me."

"Yes it is. Think John." John rolled his eyes and shook his head good naturedly.

"Sherlock, if you're joking-"

"John, this is hardly a joke to me."

"Well, then, come here you." John stood on his tiptoes as he pressed a kiss onto Sherlock's lips, sending a warm shiver down Sherlock's spine. This was where he wanted to be. This was where he belonged.


	3. Indecent Exposure

**A/N: So, this is the end, I think. Thought I'd mix it up a bit and put it in Mrs. Hudson's POV because I've never read anything from her POV before. If you have a prompts you would like me to do, (seeing as this whole thing started with a really random promt from someone on dA), just let me know and I shall what I can do. Anyways, I really enjoyed doing this, so I hope you enjoy.**

**Oh, and sorry this is so short, but I like it. DEAL WITH IT. I love you all. **

* * *

Mrs. Hudson always knew. Before the two even knew themselves. Well, that wasn't really saying much, as everyone assumed something, but Mrs. Hudson really knew. Good heavens, she could feel the tension when she first showed the boys the flat. They couldn't stay away from each other even if they tried, and dear God, it seemed like they really tried. Poor John, always denying it. Sherlock felt something, she knew he did. The way he looked at John. John was too busy playing the "not gay" card that he didn't even realize that his other half was right there in front of him.

But something changed between them after Sherlock had come back, (nearly drove Mrs. Hudson to a stroke when he did). Something clicked for the two of them. She could feel it. It was as if they were finally seeing each other for the first time. Seeing each other for what they really were. How much they meant to each other. That made her happier than she had been in a long time, to see her boys happy, at ease. Good lord, after what they'd been through, it was about time.

Mrs. Hudson, unfortunately, made the mistake of walking in on them during their first time. She was bringing them some groceries she noticed they were running low on, and she just walked in the front door like she always did, with little knock and cordial greeting. When she did enter, she was greeted with a series of grunts and embarrassed exclamations. They had their trousers round their ankles like teenagers, and thankfully Mrs. Hudson averted her eyes just in time or else she would have gotten an eye-full.

"Mrs. Hudson! Oh my God, Sherlock, I told you..."

"Oh shut up John." They had argued as Mrs. Hudson tiptoed down the stairs again, trying to keep a straight face. When she got into her flat and closed the door behind her, she burst into a fit of giggles that she couldn't stop for some time. When she finally recovered, she wiped her eyes and smiled. Yes, it was a bit indecent of them to go and have a shag in the front room, but she was happy for them.

"Mrs. Hudson, I am so sorry about, well, erm, yesterday-"

"What are you talking about dear? What about yesterday?" Was Mrs. Hudson's reply to John's efforts at attempting to mend the walk-in incident. John stared at her for a moment, then grinned sheepishly.

"Thanks Mrs. Hudson." He said softly. She gave him a wink and squeezed his arm.

"Don't worry about it luv."

"John! It's Lestrade, says he's got a triple homicide, we must hurry!" Sherlock said as he stormed out of his bedroom, quickly tying his scarf round his neck. John sighed and wearily followed after. Mrs. Hudson watched them go, taking a seat in one of the chairs. She listened as they stomped noisily down the stairs and out the door, slamming it behind them like she always hated. A small smile reached her lips. Despite all that they had been through, everything that had been thrown at them, they still managed to continue on as they always had. At Mrs. Hudson's age, it always nice to see something like that happen, even if it was a little bit late in John and Sherlock's case. But, better late than never, right?

She sat there for a few minutes, just letting everything that had happened settle in. Then, with a contented sigh, she went to their refrigerator to clear it of any body parts because she was not having body parts in that flat, no she was not.


End file.
